All the policies and enterprises related to the improvement of life since the end of the Second World War were promoted by the Ministry of Agriculture and other Ministries, and also by various governmental organizations. They tried to promote the health of Japanese people in cities, towns and villages, and to improve their life both materially and spiritually.The aims of this study are two : one is to divide the policies and enterprises into four groups on the basis of the matrixes that promoted them, and to clarify the contents of each of the policies and enterprises : the other is to demonstrate their influences upon the folk-cultural life of Japanese people by probing into definite examples of improvement in many areas of Japan.I am glad to say that, on the whole, these aims have been achieved through the analysis of relevant material and actual researches of various areas in Japan.これら諸活動は、地域の伝承生活に直接関与しようとしたために、民俗の変化に大きな影響を与えた。いくつかの地域での実践例で検討すると、竈の改良を柱とした農山村女性の家庭内労働の軽減、生活における衛生・栄養面の向上、出産・育児法の改良、家族計画の推進、煩瑣な婚礼や葬礼の簡素化、旧暦の廃止、虚礼の廃止等がなしとげられ、現在の日本人の生活に定着している。しかし、贈答習俗を背景に打つ儀礼面については、十分な成功をおさめえたかについて疑問が残る。また、諸慣習の排除を強く打ち出したがために、家庭や地域の持っていた互助機能が低下したのではないかという新たな問題も生じた。